diff --git a/requirements-dev.txt b/requirements-dev.txt
index 3310b85..d0bc3cf 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -9,12 +9,12 @@ wheel
 # Code linting
 flake8
 mccabe
-pep8<1.6,>=1.5.7
+pep8>=1.7,<1.8
 pyflakes
 
 # Documentation
-Jinja2==2.8
-MarkupSafe==0.23
-Pygments==2.1
-Sphinx==1.3.5
-docutils==0.12
+Jinja2==2.9.6
+MarkupSafe==1.0
+Pygments==2.2.0
+Sphinx==1.6.3
+docutils==0.13.1